\documentclass{standalone}
\usepackage{tikz}
\usepackage{tikz-3dplot}

\tikzset{>=latex}
\tikzstyle{axis}=[->,thick]

\begin{document}

\tdplotsetmaincoords{70}{110}
\begin{tikzpicture}[tdplot_main_coords]

    \pgfmathsetmacro{\coordlen}{5}

    \coordinate (O) at (0,0,0);

    \draw (O) node[anchor=south east]{$O$};

    \draw[axis] (O) -- (\coordlen,0,0) node[anchor=north east]{$x$};
    \draw[axis] (O) -- (0,\coordlen,0) node[anchor=west]{$y$};
    \draw[axis] (O) -- (0,0,\coordlen) node[anchor=south]{$z$};

\end{tikzpicture}

\end{document}